RESUMEN
Analysing temporal patterns in foodborne illness is important to designing and implementing effective food safety measures. The reported incidence of illness due to Salmonella in the USA. Foodborne Diseases Active Surveillance Network (FoodNet) sites has exhibited no declining trend since 1996; however, there have been significant annual trends among principal Salmonella serotypes, which may exhibit complex seasonal patterns. Data from the original FoodNet sites and penalised cubic B-spline regression are used to estimate temporal patterns in the reported incidence of illness for the top three Salmonella serotypes during 1996-2014. Our results include 95% confidence bands around the estimated annual and monthly curves for each serotype. The results show that Salmonella serotype Typhimurium exhibits a statistically significant declining annual trend and seasonality (P < 0.001) marked by peaks in late summer and early winter. Serotype Enteritidis exhibits a significant annual trend with a higher incidence in later years and seasonality (P < 0.001) marked by a peak in late summer. Serotype Newport exhibits no significant annual trend with significant seasonality (P < 0.001) marked by a peak in late summer.
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Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/microbiología , Microbiología de Alimentos , Humanos , Incidencia , Factores de Riesgo , Salmonella enteritidis/aislamiento & purificación , Salmonella typhimurium/aislamiento & purificación , Estaciones del Año , Serogrupo , Serotipificación , Factores de Tiempo , Estados Unidos/epidemiologíaRESUMEN
Potential obesity-related policy approaches have recently been receiving more attention. Although some have been implemented and others only proposed, few have been formally evaluated. We discuss the relevance, and in some cases irrelevance, of some of the types of evidence that are often brought to bear in considering obesity-related policy decisions. We discuss major methods used to generate such evidence, emphasizing study design and the varying quality of the evidence obtained. Third, we consider what the standards of evidence should be in various contexts, who ought to set those standards, as well as the inherent subjectivity involved in making policy decisions. Finally, we suggest greater transparency from both academics and policymakers in the acknowledgment of subjectivities so they can distinguish and communicate the roles of empirical evidence and subjective values in the formulation of policy.
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Política de Salud , Obesidad/prevención & control , Formulación de Políticas , Toma de Decisiones , Medicina Basada en la Evidencia , Humanos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND: A strong association has been documented between HLA-B*15:02 and carbamazepine-induced severe cutaneous adverse reactions (SCARs) in Asians. Human leucocyte antigen testing is potentially valuable in many countries to facilitate early recognition of patient susceptibility to SCARs. OBJECTIVES: To determine the cost-effectiveness of universal HLA-B*15:02 screening in preventing carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis in an ethnically diverse Malaysian population. METHODS: A hybrid model of a decision tree and Markov model was developed to evaluate three strategies for treating newly diagnosed epilepsy among adults: (i) carbamazepine initiation without HLA-B*15:02 screening (current practice); (ii) universal HLA-B*15:02 screening prior to carbamazepine initiation; and (iii) alternative treatment [sodium valproate (VPA)] prescribing without HLA-B*15:02 screening. Base-case analysis and sensitivity analyses were performed over a lifetime time horizon. Incremental cost-effectiveness ratios were calculated. RESULTS: Both universal HLA-B*15:02 screening and VPA prescribing were dominated by current practice. Compared with current practice, universal HLA-B*15:02 screening resulted in a loss of 0·0255 quality-adjusted life years (QALYs) at an additional cost of 707 U.S. dollars (USD); VPA prescribing resulted in a loss of 0·2622 QALYs at an additional cost of USD 4127, owing to estimated differences in antiepileptic treatment efficacy. CONCLUSIONS: Universal HLA-B*15:02 screening is unlikely to be a cost-effective intervention in Malaysia. However, with the emergence of an ethnically diverse population in many other countries, this may render HLA-B*15:02 screening a viable intervention when an increasing proportion of the population is at risk and an equally effective yet safer antiepileptic drug is available.
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Anticonvulsivantes/efectos adversos , Carbamazepina/efectos adversos , Antígeno HLA-B15/metabolismo , Síndrome de Stevens-Johnson/prevención & control , Adolescente , Adulto , Pueblo Asiatico/etnología , Análisis Costo-Beneficio , Eficiencia , Epilepsia/tratamiento farmacológico , Epilepsia/etnología , Humanos , Malasia/etnología , Cadenas de Markov , Tamizaje Masivo/economía , Persona de Mediana Edad , Años de Vida Ajustados por Calidad de Vida , Síndrome de Stevens-Johnson/economía , Síndrome de Stevens-Johnson/etnología , Adulto JovenRESUMEN
Genetic variation can affect drug response in multiple ways, although it remains unclear how rare genetic variants affect drug response. The electronic Medical Records and Genomics (eMERGE) Network, collaborating with the Pharmacogenomics Research Network, began eMERGE-PGx, a targeted sequencing study to assess genetic variation in 82 pharmacogenes critical for implementation of "precision medicine." The February 2015 eMERGE-PGx data release includes sequence-derived data from â¼5,000 clinical subjects. We present the variant frequency spectrum categorized by variant type, ancestry, and predicted function. We found 95.12% of genes have variants with a scaled Combined Annotation-Dependent Depletion score above 20, and 96.19% of all samples had one or more Clinical Pharmacogenetics Implementation Consortium Level A actionable variants. These data highlight the distribution and scope of genetic variation in relevant pharmacogenes, identifying challenges associated with implementing clinical sequencing for drug treatment at a broader level, underscoring the importance for multifaceted research in the execution of precision medicine.
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Bases de Datos Genéticas , Variación Genética , Genómica , Farmacogenética , Anciano , Registros Electrónicos de Salud , Femenino , Humanos , Masculino , Persona de Mediana Edad , Medicina de Precisión/métodosRESUMEN
AIMS: Using Bayesian methods that do not require the definition of a gold standard, the diagnostic sensitivity and specificity of a real-time polymerase chain reaction (PCR) assay are compared to those of an enriched culture assay for detection of Campylobacter in enriched comminuted chicken samples. METHODS AND RESULTS: Food Safety and Inspection Service comminuted chicken samples were collected from production facilities across the United States. Enriched samples were examined using a commercial real-time PCR kit and plated for culture. Allowing for conditional dependence between these approaches and defining relatively uninformed prior distributions, the 'no gold standard' Bayesian methods generated estimates of the means (95% credible interval) of the posterior distributions for sensitivity and specificity of the PCR as 93% (79, 100%) and 95% (87, 100%) respectively. The estimated sensitivity implies a mean false negative frequency of 7%. The estimated means of the posterior distributions for sensitivity and specificity of the culture assay were 91% (76, 100%) and 96% (88, 100%) respectively. In this case, the mean false negative frequency is 9%. Graphical comparisons of the posterior distributions with their corresponding prior distributions suggested only subtle differences in the sensitivities of both tests, but the posterior distributions for specificities are substantially more certain than the prior distributions. CONCLUSIONS: The study suggests that the commercial real-time PCR assay is a more sensitive screening test that would provide timelier negative test results. The modest 1% reduction in specificity of this PCR assay, as compared to an enriched culture assay, is less of a concern for regulatory testing programs if a culture-based confirmatory assay is applied to all presumptive positive samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The sensitivity and specificity of a PCR assay and a culture assay for Campylobacter in comminuted poultry produced in the United States were estimated. The PCR assay was shown to be an appropriate alternative screening test.
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Campylobacter/genética , Pollos/microbiología , Inocuidad de los Alimentos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Animales , Teorema de Bayes , Campylobacter/aislamiento & purificación , Reacciones Falso Negativas , Humanos , Aves de Corral , Sensibilidad y Especificidad , Estados UnidosRESUMEN
The Clinical Genome Resource (ClinGen) is a National Institutes of Health (NIH)-funded collaborative program that brings together a variety of projects designed to provide high-quality, curated information on clinically relevant genes and variants. ClinGen's EHR (Electronic Health Record) Workgroup aims to ensure that ClinGen is accessible to providers and patients through EHR and related systems. This article describes the current scope of these efforts and progress to date. The ClinGen public portal can be accessed at www.clinicalgenome.org.
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Registros Electrónicos de Salud/tendencias , Farmacogenética/tendencias , Bases de Datos Genéticas , Variación Genética , Humanos , Medicina de PrecisiónAsunto(s)
Dermabrasión/métodos , Queratinocitos/trasplante , Terapia por Láser/métodos , Melanocitos/trasplante , Trasplante de Piel/métodos , Vitíligo/terapia , Adulto , Anciano , Vendajes , Femenino , Humanos , Láseres de Gas , Masculino , Persona de Mediana Edad , Pigmentación de la Piel , Resultado del Tratamiento , Técnicas de Cierre de Heridas , Adulto JovenRESUMEN
Human illness attribution is recognized as an important metric for prioritizing and informing food-safety decisions and for monitoring progress towards long-term food-safety goals. Inferences regarding the proportion of illnesses attributed to a specific commodity class are often based on analyses of datasets describing the number of outbreaks in a given year or combination of years. In many countries, the total number of pathogen-related outbreaks reported nationwide for an implicated food source is often fewer than 50 instances in a given year and the number of years for which data are available can be fewer than 10. Therefore, a high degree of uncertainty is associated with the estimated fraction of pathogen-related outbreaks attributed to a general food commodity. Although it is possible to make inferences using only data from the most recent year, this type of estimation strategy ignores the data collected in previous years. Thus, a strong argument exists for an estimator that could 'borrow strength' from data collected in the previous years by combining the current data with the data from previous years. While many estimators exist for combining multiple years of data, most either require more data than is currently available or lack an objective and biologically plausible theoretical basis. This study introduces an estimation strategy that progressively reduces the influence of data collected in past years in accordance with the degree of departure from a Poisson process. The methodology is applied to the estimation of the attribution fraction for Salmonella and Escherichia coli O157:H7 for common food commodities and the estimates are compared against two alternative estimators.
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Brotes de Enfermedades , Infecciones por Escherichia coli/epidemiología , Escherichia coli O157/fisiología , Microbiología de Alimentos/métodos , Enfermedades Transmitidas por los Alimentos/epidemiología , Salmonella/fisiología , Brotes de Enfermedades/estadística & datos numéricos , Infecciones por Escherichia coli/microbiología , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Modelos Teóricos , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/microbiología , Factores de TiempoRESUMEN
Pegylated interferon-α (PEG-IFN-α or PEG-IFN 2a and 2b)- and ribavirin (RBV)-based regimens are the mainstay for treatment of hepatitis C virus (HCV) genotype 1. IFNL3 (IL28B) genotype is the strongest baseline predictor of response to PEG-IFN-α and RBV therapy in previously untreated patients and can be used by patients and clinicians as part of the shared decision-making process for initiating treatment for HCV infection. We provide information regarding the clinical use of PEG-IFN-α- and RBV-containing regimens based on IFNL3 genotype.
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Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Interleucinas/genética , Polietilenglicoles/uso terapéutico , Antivirales/administración & dosificación , Quimioterapia Combinada , Pruebas Genéticas/normas , Genotipo , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Interferones , Polietilenglicoles/administración & dosificación , Polimorfismo de Nucleótido Simple/genética , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/uso terapéutico , Ribavirina/administración & dosificación , Ribavirina/uso terapéutico , Resultado del TratamientoRESUMEN
AIMS: The fitting of statistical distributions to microbial sampling data is a common application in quantitative microbiology and risk assessment applications. An underlying assumption of most fitting techniques is that data are collected with simple random sampling, which is often times not the case. This study develops a weighted maximum likelihood estimation framework that is appropriate for microbiological samples that are collected with unequal probabilities of selection. METHODS AND RESULTS: A weighted maximum likelihood estimation framework is proposed for microbiological samples that are collected with unequal probabilities of selection. Two examples, based on the collection of food samples during processing, are provided to demonstrate the method and highlight the magnitude of biases in the maximum likelihood estimator when data are inappropriately treated as a simple random sample. CONCLUSIONS: Failure to properly weight samples to account for how data are collected can introduce substantial biases into inferences drawn from the data. SIGNIFICANCE AND IMPACT OF THE STUDY: The proposed methodology will reduce or eliminate an important source of bias in inferences drawn from the analysis of microbial data. This will also make comparisons between studies and the combination of results from different studies more reliable, which is important for risk assessment applications.
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Contaminación de Alimentos/análisis , Microbiología de Alimentos , Proyectos de Investigación , Animales , Sesgo , Campylobacter/aislamiento & purificación , Bovinos , Pollos , Simulación por Computador , Funciones de Verosimilitud , Carne/microbiología , Probabilidad , Medición de Riesgo/métodos , Salmonella/aislamiento & purificaciónRESUMEN
Understanding the human genome and its interaction with the environment has the potential to change medical care by tailoring interventions to the precise needs of the individual patient. Little of this knowledge is currently being used in care. There are well recognized barriers to its use including lack of sufficient evidence of benefit, inadequate education of the provider workforce, concerns about privacy and reimbursement. However, there are also gaps in the current healthcare delivery system, particularly between traditional public health departments and clinical care that impede the translation of knowledge into practice. While this problem is not limited to genomics, the purpose of this article is to identify these gaps and propose potential solutions using examples from genomic medicine from the perspective of the United States healthcare system.
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Genómica , Salud Pública/métodos , Neoplasias de la Mama/genética , Medicina Basada en la Evidencia/métodos , Femenino , Genoma Humano , Política de Salud , Humanos , Recién Nacido , Sistemas de Registros Médicos Computarizados , Tamizaje Neonatal/métodos , Neoplasias Ováricas/genética , Farmacogenética/métodos , Medicina de Precisión/métodos , Práctica de Salud Pública , Investigación Biomédica TraslacionalRESUMEN
INTRODUCTION: The age-standardized mortality rate for cervical cancer in Ghana, West Africa is more than three times the global cervical cancer mortality rate (27.6/100,000 vs. 7.8/100,000 respectively). The Pap test and visual inspection with acetic acid are available at public and private hospitals in Ghana. Approximately, 2.7% of Ghanaian women obtain cervical cancer screenings regularly. Men in middle-income countries play a key role in cervical cancer prevention. Increasing spousal support for cervical cancer screening may increase screening rates in Ghana. METHODS: Five focus groups were conducted with Ghanaian men (N = 29) to assess their cervical cancer and cervical cancer screening knowledge and beliefs. The qualitative data was analyzed via indexed coding. RESULTS: Targets for education interventions were identified including inaccurate knowledge about cervical cancer and stigmatizing beliefs about cervical cancer risk factors. Cultural taboos regarding women's health care behaviours were also identified. Several participants indicated that they would be willing to provide spousal support for cervical cancer screening if they knew more about the disease and the screening methods. CONCLUSIONS: Men play a significant role in the health behaviours of some Ghanaian women. Cervical cancer education interventions targeting Ghanaian men are needed to correct misconceptions and increase spousal support for cervical cancer screening.
Asunto(s)
Detección Precoz del Cáncer/psicología , Conocimientos, Actitudes y Práctica en Salud , Hombres/psicología , Neoplasias del Cuello Uterino/diagnóstico , Ácido Acético , Adolescente , Adulto , Cultura , Femenino , Grupos Focales , Ghana , Examen Ginecologíco/psicología , Educación en Salud , Humanos , Indicadores y Reactivos , Masculino , Tamizaje Masivo , Hombres/educación , Persona de Mediana Edad , Prueba de Papanicolaou/psicología , Apoyo Social , Tabú , Neoplasias del Cuello Uterino/prevención & control , Frotis Vaginal/psicología , Adulto JovenRESUMEN
Missing in metastasis (MIM) is a member of newly emerged inverse Bin-Amphiphysin-Rvs (BAR) domain protein family and a putative metastasis suppressor. Although reduced MIM expression has been associated with bladder, breast and gastric cancers, evidence for the role of MIM in tumor progression remains scarce and controversial. Herein we characterized a MIM knockout mouse strain and observed that MIM-deficient mice often developed enlarged spleens. Autopsy and histological analysis revealed that nearly 78% of MIM(-/-) mice developed tumors with features similar to diffuse large B lymphoma during a period from 1 to 2 years. MIM(-/-) mice also exhibited abnormal distribution of B cells in lymphoid organs with decrease in the spleen but increase in the bone marrow and the peripheral blood. Furthermore, the bone marrow of MIM(-/-) mice contained a higher percentage of pre-B2 cells but fewer immature B-cells than wild-type mice. In response to CXCL13, a B-cell chemokine released from splenic stromal cells, MIM-deficient B-cells did not undergo chemotaxis or morphological changes in response to the chemokine and also did not internalize CXCR5, the receptor of CXCL13. Microarray analyses demonstrated that MIM is the only member of the I-BAR domain family that was highly expressed in human B cells. However, low or absent MIM expression was common in either primary B-cell malignancies or established B-cell acute lymphocytic leukemia or lymphomas. Thus, our data demonstrate for the first time an important role for MIM in B-cell development and suggest that predisposition of MIM-null mice to lymphomagenesis may involve aberrant interactions between B lineage cells and the lymphoid microenvironment.
Asunto(s)
Transformación Celular Neoplásica/genética , Predisposición Genética a la Enfermedad , Linfoma de Células B Grandes Difuso/genética , Proteínas de Microfilamentos/genética , Proteínas de Neoplasias/genética , Animales , Linfocitos B/efectos de los fármacos , Linfocitos B/metabolismo , Médula Ósea/metabolismo , Células Cultivadas , Quimiocina CXCL13/farmacología , Quimiotaxis/efectos de los fármacos , Femenino , Granulocitos/metabolismo , Humanos , Leucocitos Mononucleares/metabolismo , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Masculino , Ratones , Ratones Noqueados , Proteínas de Microfilamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Receptores CXCR5/metabolismo , Bazo/metabolismo , Bazo/patología , Linfocitos T/metabolismoRESUMEN
BACKGROUND: The role of germline and somatic SMARCB1 gene mutations in malignant rhabdoid tumour (MRT) predisposition is well known. Germline SMARCB1 mutations have also recently been identified in a subset of individuals with schwannomatosis. Surprisingly, MRT predisposition and schwannomatosis have never been reported to co-occur in a family. The correlation between genotype and phenotype for mutations in SMARCB1 has not been determined. RESULTS: We have identified a germline 2631 bp duplication that includes exon 6 of SMARCB1 in a unique family with a four generation history of MRT predisposition and schwannomatosis. This duplication segregates with disease in individuals affected with both conditions, linking MRT predisposition and schwannomatosis as components of the same syndrome in this family. CONCLUSION: The unique combination of tumours that result from the duplication described in this report may provide important clues about the mechanisms that influence the phenotype associated with a given SMARCB1 mutation.
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Proteínas Cromosómicas no Histona/genética , Proteínas de Unión al ADN/genética , Duplicación de Gen , Neurilemoma/genética , Tumor Rabdoide/genética , Factores de Transcripción/genética , Secuencia de Bases , Exones , Familia , Genotipo , Mutación de Línea Germinal , Humanos , Datos de Secuencia Molecular , Neurilemoma/patología , Linaje , Fenotipo , Tumor Rabdoide/patología , Proteína SMARCB1RESUMEN
Here we confirm that intranasal (IN) dry powder anthrax vaccine formulations are able to protect rabbits against aerosol challenge 9 weeks after a single immunization. The optimum dose of rPA in our dry powder anthrax vaccine formulation in rabbits was experimentally determined to be 150microg and therefore was chosen as the target dose for all subsequent experiments. Rabbits received a single dose of either 150microg rPA, 150microg rPA+150microg of a conjugated 10-mer peptide representing the Bacillus anthracis capsule (conj), or 150microg of conj alone. All dry powder formulations contained MPL and chitosan (ChiSys). Significant anti-rPA titers and anthrax lethal toxin neutralizing antibody (TNA) levels were seen with both rPA containing vaccines, although rPA-specific IgG and TNA levels were reduced in rabbits immunized with rPA plus conj. Nine weeks after immunization, rabbits were exposed to a mean aerosol challenge dose of 278 LD50 of Ames spores. Groups immunized with rPA or with rPA+conj had significant increases in survivor proportions compared to the negative control group by Logrank test (p=0.0001 and 0.003, respectively), and survival was not statistically different for the rPA and rPA+conj immunized groups (p=0.63). These data demonstrate that a single immunization with our dry powder anthrax vaccine can protect against a lethal aerosol spore challenge 9 weeks later.
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Vacunas contra el Carbunco/administración & dosificación , Vacunas contra el Carbunco/inmunología , Carbunco/inmunología , Carbunco/prevención & control , Adyuvantes Inmunológicos/farmacología , Administración Intranasal , Aerosoles , Compuestos de Alumbre/farmacología , Animales , Anticuerpos Antibacterianos/análisis , Anticuerpos Antibacterianos/biosíntesis , Antígenos Bacterianos/inmunología , Cápsulas Bacterianas/inmunología , Química Farmacéutica , Ensayo de Inmunoadsorción Enzimática , Femenino , Inmunoglobulina G/análisis , Inmunoglobulina G/biosíntesis , Indicadores y Reactivos , Pruebas de Neutralización , Polvos , Conejos , Soluciones , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/inmunologíaRESUMEN
An intranasal vaccine targeting the Bacillus anthracis toxin and vegetative bacterium was tested for the ability to protect immunized rabbits against aerosol B. anthracis spore exposure. Rabbits were vaccinated intranasally with PA-based vaccines formulated as dry powders with or without chitosan (ChiSys, Archimedes Development Limited), a compound that exhibits muco-adhesive properties, or as a liquid. Formulations also contained MPL adjuvant and PA. Some vaccines contained PA conjugated to a 10-mer peptide of the poly-d-glutamic acid capsule of B. anthracis. Rabbits were immunized on days 0 and 28 and aerosol challenged with an average 250LD50 Ames spores on day 85. Serum antibody was measured before and after challenge. Significant anti-PA serum IgG levels were obtained, particularly with use of ChiSys based formulations. PA-Conj induced significant anti-capsule responses, although a formulation containing free capsule peptide did not. All immunized rabbits survived the challenge, but differences in morbidity, as evidenced by anorexia, between vaccine groups were observed. Only rabbits immunized with PA+PA-Conj appeared normal throughout the post-challenge observation period (14 days), while all that received PA with the free capsule peptide appeared ill at times as evidenced by a failure to eat normally. One negative control rabbit received a lower inhaled spore dose (183LD50) and survived the challenge, although it was anorexic post-challenge. It also had a high level of anti-LF antibodies in its convalescent serum (5400 U/ml), indicating an extensive infection. In contrast, 75% of the immunized rabbits had no LF-specific antibody in their post-challenge sera, and the rest had low levels (< or = 138 U/ml), indicating that infections resulting in toxin production were avoided or greatly reduced. Thus, intranasal immunization with a chitosan-based powder vaccine combining PA and capsule epitopes provided superior protection against B. anthracis infection compared to a single antigen (PA) vaccine, as evidenced by a reduction in morbidity and prevention of death.
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Vacunas contra el Carbunco/inmunología , Carbunco/prevención & control , Antígenos Bacterianos/inmunología , Bacillus anthracis/inmunología , Toxinas Bacterianas/inmunología , Exposición por Inhalación , Adyuvantes Inmunológicos/administración & dosificación , Administración Intranasal , Aerosoles , Animales , Anorexia , Carbunco/patología , Vacunas contra el Carbunco/administración & dosificación , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/genética , Cápsulas Bacterianas/inmunología , Toxinas Bacterianas/genética , Quitosano , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Inmunoglobulina G/sangre , Lípido A/análogos & derivados , Lípido A/inmunología , Pruebas de Neutralización , Ácido Poliglutámico/genética , Conejos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunologíaRESUMEN
Previous studies indicated that antigen receptor (TcR) stimulation of mature T cells induced rapid generation of reactive oxygen species (ROS). The goal of the current study was to examine the role(s) of ROS in TcR signal transduction, with a focus upon the redox-sensitive MAPK family. TcR cross-linking of primary human T blasts and Jurkat human T cells rapidly activated the ERK, JNK, p38 and Akt kinases within minutes, and was temporally associated with TcR-stimulated production of hydrogen peroxide (H(2)O(2)). TcR-induced activation of ERK was selectively augmented and sustained in the presence of pharmacologic antioxidants that can quench or inhibit H(2)O(2) production (NAC, MnTBAP and Ebselen, but not DPI), while activation of JNK and Akt were largely unaffected. This was paralleled by concurrent changes in MEK1/2 phosphorylation, suggesting that ROS acted upstream of MEK-ERK activation. Molecular targeting of H(2)O(2) by overexpression of peroxiredoxin II, a thioredoxin dependent peroxidase, also increased and sustained ERK and MEK activation upon TcR cross-linking. Enhancement of ERK phosphorylation by antioxidants correlated with increased and sustained serine phosphorylation of the src-family kinase lck, a known ERK substrate. Thus, the data suggest that TcR-stimulated production of hydrogen peroxide negatively feeds back to dampen antigen-stimulated ERK activation and this redox-dependent regulation may serve to modulate key steps in TcR signaling.
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Peróxido de Hidrógeno/farmacología , Proteínas Quinasas JNK Activadas por Mitógenos , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Receptores de Antígenos de Linfocitos T/metabolismo , Serina/metabolismo , Antioxidantes/metabolismo , Antioxidantes/farmacología , Azoles/metabolismo , Complejo CD3/biosíntesis , Reactivos de Enlaces Cruzados/farmacología , Activación Enzimática , Humanos , Immunoblotting , Isoindoles , Células Jurkat , MAP Quinasa Quinasa 4 , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Compuestos de Organoselenio/metabolismo , Oxidación-Reducción , Peroxidasas/metabolismo , Peroxirredoxinas , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Especies Reactivas de Oxígeno , Transducción de Señal , Linfocitos T/metabolismo , Tiorredoxinas/metabolismo , Factores de Tiempo , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
We screened 120 children with sporadic multiple congenital anomalies and either growth or mental retardation for uniparental disomy (UPD) or subtelomeric deletions. The screening used short tandem repeat polymorphisms (STRP) from the subtelomeric regions of 41 chromosome arms. Uninformative marker results were reanalyzed by using the next available marker on that chromosome arm. In total, approximately 25,000 genotypes were generated and analyzed for this study. Subtelomeric deletions of 1 Mb in size were excluded for 27 of 40 chromosome arms. Among the 120 subjects none was found to have UPD, but five subjects (4%, 95% confidence interval 1-9%) were found to have a deletion or duplication of one or more chromosome arms. We conclude that UPD is not a frequent cause of undiagnosed multiple congenital anomaly syndrome. In addition, we determined that 9p and 7q harbor chromosome length variations in the normal population. We conclude that subtelomeric marker analysis is effective for the detection of subtelomeric duplications and deletions, although it is labor intensive. Given a detection rate that is similar to prior studies and the large workload imposed by STRPs, we conclude that STRPs are an effective, but impractical, approach to the determination of segmental aneusomy given current technology.